As a core facility, the Morphological Studies Core is a resource for the Program Project. Its function is to provide documentation of the gross and histological changes of the knee joint specimens studied by the respective projects. This descriptive information is correlated with the specific measure of each project, providing a multi-disciplinary analysis of age-related changes in human knee joint tissues. The Specific Aims of the Morphology Core are: I. Harvest human knee joints obtained at autopsy from tissue banks from donors of both genders, all races and a distribution of age from the second to the ninth decades. A. Record (photographs and sketches on a report form) and assess pathological conditions of the knee. Classify any degradative changes to the tibial, femoral and patellar cartilage using a modified Outerbridge grading system. Classify any degradative changes to the menisci, and ligaments. B. Harvest cartilage from the femoral and tibial condylar surfaces for distribution to the tissue culture core. Drill osteochondral plugs from the femoral condylates for the biomechanics project. C. Obtain osteochondral slabs from the harvested human knee joints for histomorphologic and histochemical assessment. II. Produce microradiographs of the cut slabs using a Faxitron x-ray unit. Measure the thickness and density of the subchondral plate and correlate with age, gender, body mass index (BMI) and gross morphological grade. III. Obtain histomorphometric measurements from the cut slabs of cartilage height, surface roughness, safranin O intensity, cell count and cell density, and correlate with age, gender, body mass index (BMI) and gross morphological grade. IV. Obtain histomorphometric measurements for Project 3 rabbit condyles of cartilage, height, surface roughness, relative proteoglycan by safranin O intensity, cell count and cell density.